Hibernate 一对多关联的问题
想测试一下两个表数据的保存,其中表Employee引用了Department表的主键作为外键
Department的hbm文件:
<class name= "com.sunny.vo.Department " table= "department " schema= "dbo " catalog= "test ">
<id name= "id " type= "java.lang.Integer ">
<column name= "id " />
<generator class= "identity "> </generator>
</id>
<property name= "dname " type= "java.lang.String ">
<column name= "dname " length= "10 " />
</property>
<set name= "employees " inverse= "true ">
<key>
<column name= "pid " not-null= "true " />
</key>
<one-to-many class= "com.sunny.vo.Employee " />
</set>
</class>
Employee的hbm文件:
<hibernate-mapping>
<class name= "com.sunny.vo.Employee " table= "employee " schema= "dbo " catalog= "test ">
<id name= "id " type= "java.lang.Integer ">
<column name= "id " />
<generator class= "identity " />
</id>
<many-to-one name= "department " class= "com.sunny.vo.Department " fetch= "select ">
<column name= "pid " not-null= "true " />
</many-to-one>
<property name= "name " type= "java.lang.String ">
<column name= "name " length= "10 " />
</property>
</class>
</hibernate-mapping>
在测试时显示出错:
org.springframework.dao.DataIntegrityViolationException: Hibernate operation: could not insert: [com.sunny.vo.Employee]; SQL [insert into test.dbo.employee (pid, name) values (?, ?) select scope_identity()]; [Microsoft][SQLServer 2000 Driver for JDBC][SQLServer]INSERT 语句与 COLUMN FOREIGN KEY 约束 'FK_employee_department ' 冲突。该冲突发生于数据库 'test '，表 'department ', column 'id '。; nested exception is java.sql.SQLException: [Microsoft][SQLServer 2000 Driver for JDBC][SQLServer]INSERT 语句与 COLUMN FOREIGN KEY 约束 'FK_employee_department ' 冲突。该冲突发生于数据库 'test '，表 'department ', column 'id '。
java.sql.SQLException: [Microsoft][SQLServer 2000 Driver for JDBC][SQLServer]INSERT 语句与 COLUMN FOREIGN KEY 约束 'FK_employee_department ' 冲突。该冲突发生于数据库 'test '，表 'department ', column 'id '。
是哪里出错了?请帮忙了
[解决办法]
在插入时候发生了外键约束,
不存在你向employee表中插入数据时对应的department.
[解决办法]
当然报错拉，在Employee的hbm文件:
<many-to-one name= "department " class= "com.sunny.vo.Department " fetch= "select ">
<column name= "pid " not-null= "true " />
</many-to-one>
你设置他为只select的，插入数据肯定报错了．．．
改为：fetch= "select,insert,update,delete " 就可以操作所有的了
建议你去看看Ｈibernate基础语法～
[解决办法]
奉劝不要用一对多之类的,很难掌握他的性能情况
